The present invention relates to an electronic musical apparatus, and particularly relates to an automatic performance apparatus of the type constructed to mute a part of automatic performance when a manual implement is operated to play the same part, and constructed to restore the muted part at an adequate break point of musical passages or phrases when the operation of the manual implement is quitted.
The conventional automatic performance apparatus is operated in response to a tempo clock to read out performance data which is provisionally recorded for carrying out an automatic performance. Generally, the automatic performance apparatus stores the automatic performance data divided into a plurality of parallel parts, and is provided with a minus-one function such that one or more parts is intentionally muted while the remaining parts are sounded during the automatic performance. The minus-one function allows a player to enjoy manual performance for the muted part while keeping the automatic performance of the remaining parts. The manual performance by the minus-one function may be continued throughout one complete music composition. However, in another case, a player may wish to add ad lib manual performance for a desired period, and may wish to fill automatic performance for the rest periods a part by part. For this purpose, a modified automatic performance apparatus is proposed in Japanese Patent Application Laid-open No. 5-173561. The disclosed apparatus is constructed to temporarily mute a selected part during the automatic performance when a manual implement such as a keyboard is played to substitute the selected part by corresponding manual performance, and is constructed to restore the automatic performance of the selected part after the play of the keyboard is discontinued. However, in such a temporary minus-one play, the muting and the restoring are controlled a measure by measure. The selected part is muted for several measures including a leading measure where the keyboard is initially touched. The automatic performance of the muted part is restored from a subsequent measure immediately after the manual play of the keyboard is stopped. Therefore, the automatic performance may be incidentally or suddenly restarted from a musically inadequate point rather than musically adequate points.